In our critically-ill, initially non-septic patients, circulating E-and P-selectin at ICU admission were found to be the only independent risk factors associated with sepsis development in time. In
addition, ROC curve analysis denoted that sE- and especially sP-selectin have better prognostic accuracy than CRP and PCT in identifying patients who will subsequently develop sepsis. The question remains whether the increased amounts of soluble E-selectin in blood result from endothelial injury rather than mere activation.E-selectin detected in the blood of normal subjects had no evident
cytoplasmic domain suggesting that shedding rather than injury accounts for the low level expression in vivo. More than 80% of our patients met SIRS criteria at ICU admission. However, elevated sE- and sP-selectin levels were associated with the presence of sepsis and not with SIRS presence, probably denoting that these circulating molecules better reflect endothelial dysfunction-injury
than endothelial activation. Furthermore, the ability of soluble E- and P-selectins to differentiate patients who would subsequently develop clinical sepsis may reflect the important role of both the
endothelium and leukocytes in the septic course; their interaction is of prominent pro-inflammatory significance, with selectins playing a key role in this process.
Approximately half of our subjects were trauma patients(N = 45). We therefore sought to analyze these patients separately. Trauma patients revealed rather similar profiles with the totality of
our cohort, since circulating levels of E- and P-selectin were also associated with the subsequent appearance of sepsis. Our results suggest that measurements of circulating E- and P-selectins might have a future role in routine ICU clinical practice, although larger studies are needed before final conclusions can be drawn. Nevertheless, early identification of critically ill patients
who will become septic, or even monitoring the septic process by means of serial measurements of endothelial adhesion molecules in the ICU, might add to the patient’s care. It should be noted that
the use of the needed ELISAs carries a moderately higher cost than several everyday routine laboratory tests. In this respect the use of the activated partial thromboplastin time (aPTT) biphasic wave form (BWP), a phenomenon caused by the formation of a complex
between CRP and lipoproteins, has been shown to be an inexpensive way that provides information on early sepsis, the presence of severe sepsis and the prognosis of septic patients. How-
ever, it is still unknown if aPTT BWP could differentiate between initially non-septic patients who will subsequently develop sepsis or not.
Our study has the limitation of not analyzing sepsis severity
variants (i.e. severe sepsis, septic shock) due to the limited size
our sample, but we did demonstrate associations between baseline
biomarkers and future sepsis appearance. On the other hand, the
fact that our investigation was performed at one intensive care unit
implies that the quality of care and ICU epidemiology (parameters
that might differ among centers) were not potential confounding
factors for the obtained results.